Tokyo claimed "mild" summer weather made it an ideal candidate to host the Olympic Games in 2020. Consider that an oversell, as athletes could now be in for the hottest Olympics on record. The daily maximum temperature recorded at a Summer Olympics was in Sydney, Australia, in 2000 and Beijing, China, in 2008. But the 20-year average in Tokyo for the dates of this year's Games is even higher, per the Guardian. And Japan's weather agency forecasts this period "will be hotter than average," per AFP. Yahoo Sports columnist Dan Wetzel predicts it will be like competing "inside a steam bath," with temperatures around 90 degrees Fahrenheit and high dew point and humidity levels. Makoto Yokohari, an adviser to the Tokyo Organizing Committee, previously told Reuters that high temperatures and humidity would combine for "the worst [Games] in history."
Marathon and race walk events will take place in Sapporo, 500 miles north of Tokyo, where temperatures are cooler. But athletes in Japan's largest city—many of whom will arrive days before their events, with little time to acclimatize—may have to compete under conditions that the environment ministry considers dangerous for exercise. It recommends residents avoid regular or heavy exercise when the wet bulb globe temperature—a measurement taking into account temperature, humidity, wind speed, sun angle, and cloud cover—exceeds 87.8 degrees Fahrenheit. The WBGT stood at 89.24 degrees on Tuesday, as practicing beach volleyball players complained that sand was too hot for their feet, per the Guardian. Haruo Ozaki, chairman of the Tokyo Medical Association, has warned of "high risks of heatstroke at events such as competitive walking, triathlon and beach volleyball," per AFP. (Read more Tokyo Olympics stories.)